Patients with pancreatic adenocarcinoma have an extremely high mortality rate. Curative surgery would be more common if early differential diagnosis were feasible. Our group has demonstrated that the micro-leukocyte adherence inhibition assay (micro-LAI) can successfully and specifically detect the presence of pancreatic cancer. In our continuing study to determine the sensitivity of the assay for detection of early cancer, we require a stable, standardized source of pancreas tumor antigen. This will be accomplished by propagating several established low-passage pancreatic adenocarcinoma cell lines in athymic (nude) mice. A membrane extract and a 1 M perchloric acid (PCA) soluble extract of each of the lines will be analyzed by micro-LAI and the most consistently reactive tumor line will be grown periodically in large quantity and stable soluble antigen will be prepared for routine use in the assay. Reactive PCA extracts will be biochemically fractionated and assayed to yield a purified LAI-defined antigen. LAI-defined antigens will also be purified from patients' sera and ascites fluid. Xenogeneic antisera will be prepared against the purified antigen preparations and they will be immunochemically and biochemically compared by serological assays and by 2-dimensional isoelectric-focusing electrophoresis. Antisera against the PCA soluble antigen will also be utilized in serological assays to identify and quantitate serum and ascites antigens during their purification. Radioiodinated purified antigen will be prepared and a radioimmunoassay (RIA) will be developed using the most avid xenogeneic antitumor antibodies. Preliminary RIA screening of selected sera from our serum bank will be carried out in a blind fashion. A portion of the pancreas cancer specific antibodies will be labeled with Iodine-131 and assayed to determine their suitability for use in external computerized photoscanning for tumor localization. This project will significantly improve the micro-LAI assay and the serological and biochemical data obtained will complement the clinical information currently being assessed.